The invention relates to a radial piston pump having the features of claim 1.
Radial piston pumps are a specific type of displacement pump having a plurality of pistons which are arranged in a star shape around and perpendicular to the drive axis. Said radial piston pumps can be acted on with pressure medium from the inside or from the outside and are generally suitable for constant high pressures.
In the case of externally loaded radial piston pumps which are supported at the inside, the pistons are supported on an eccentric which is situated on the driveshaft and are moved in a reciprocating fashion in the cylinders of a stationary cylinder block by the rotation of said eccentric. Here, the pressure medium flow is controlled by means of suction and pressure valves attached at the outside. The cylindrical pistons conventionally have, for guidance in the cylinders, a relatively large installation length in relation to the piston stroke, that is to say have a large casing height of the piston head, as a result of which a rectilinear movement of the pistons in the cylinders is ensured. Here, it is to be taken into consideration that, in the case of the conventionally single-piece pistons, transverse forces are unavoidable as a result of the eccentric drive, even if the support of the pistons on the eccentric takes place in a virtually punctiform manner, for example by means of a convex contact face. The conventional construction therefore results in a comparatively large outer diameter of the pump.
The different systems for radial piston pumps are described for example in H. Ebertshäuser/S. Helduser “Fluidtechnik von A bis Z” [“Fluid technology from A to Z”], Vereinigte Fachverlage, Mainz, 2nd edition 1995, pages 275-276.
It is the aim of the invention to create an improved radial piston pump.